CH707417B1 - A portable electronic device and method for manufacturing such a device. - Google Patents

Abstract

The invention relates to a portable electronic device capable of producing information, this portable electronic device (1) comprising a body (2) arranged to be attached to a user and at least one electronic assembly (16) to produce the information , the body (2) of the portable electronic device (1) consisting of a layer of plastic material which gives the portable electronic device (1) a shape and a thickness, characterized in that the portable electronic device (1) comprises a first sealed plastic film (4) which serves to coat the layer of plastic material, and a second impermeable plastic film (36) secured to a periphery (38) of the first waterproof plastic film (4), and in that the whole electronics (16) for developing the information is disposed between the first and second sealed plastic films (4, 36). The invention also relates to a method of manufacturing a portable electronic device.

Description

The present invention relates to a flexible portable electronic device and a method of manufacturing such a device. The present invention relates in particular to a flexible portable electronic device of the wristwatch type and its method of manufacture.

A flexible portable electronic device such as that described in the European patent application EP 1 158 375 A1 in the name of the applicant comprises essentially a flexible body arranged to be attached to a body part of a user as a wrist . In one place of the length of the flexible body is formed a cavity in which are housed an electronic assembly for developing information, a digital information display device for displaying the information developed by the electronic assembly, and a source of information. electrical energy to power the electronic assembly.

The manufacture of such a portable electronic device requires overmolding of the cavity by means of a polymer which is characterized by high flexibility and elasticity. Suitable polymers for such an application include certain elastomers such as natural rubber, styrene-butadiene copolymer or even thermoplastic polyurethane. Other materials of the flexible thermoplastic polymer type such as a polyamide or a silicone are also conceivable. This overmolding operation which aims to give the portable electronic device its final shape and thickness, however, has two notable drawbacks. First, some materials such as elastomers do not have sufficient sealing to protect the electronic components of the portable electronic device against moisture or against certain gases. Indeed, during the life of the portable electronic device, the water vapor and the gases diffuse slowly through the elastomer and can reach the electronic components, which affects the operation of these electronic components and may even lead to their destruction. The second disadvantage of the overmolding operation lies in the high temperatures put into play by certain elastomers or plastic materials during their overmoulding. Such high temperatures are not compatible with electronic components and would irreversibly damage these electronic components. For the overmolding operation of the flexible portable electronic device, it is therefore limited in the choice of materials usable by the processing temperatures of these materials.

The present invention aims to overcome these disadvantages by providing a flexible portable electronic device that is waterproof and allows, if necessary, to use overmolding techniques at high temperatures.

For this purpose, the present invention relates to a portable electronic device capable of producing information, the portable electronic device comprising a body arranged to be attached to a user and at least one electronic unit for developing the information, the body of the portable electronic device consisting of a layer of plastic material which gives the portable electronic device a shape and a thickness, characterized in that the portable electronic device comprises a first impermeable plastic film which serves as a coating to the layer of plastic material and a second impermeable plastic film secured to the first impermeable plastic film, and in that the electronic assembly for developing the information is disposed between the first and second impermeable plastic films.

With these features, the present invention provides a portable electronic device whose body, formed of a layer of plastic material, is coated with a first impermeable plastic film. It is therefore no longer limited in the choice of material with which the body of the portable electronic device is made. Indeed, the first plastic film whose body of the portable electronic device is coated forms a completely moisture-proof barrier. Therefore, even if the body of the portable electronic device is made of a material through which moisture and gases can diffuse, the components of the electronic information-developing assembly disposed within a pocket delimited by the second waterproof plastic film which is secured to the first sealed plastic film, are perfectly protected from moisture.

According to a complementary feature of the invention, the body of the portable electronic device consists of a layer of flexible plastic material. Advantageously, the body of the portable electronic device is made of elastomer.

According to yet another characteristic of the invention, the portable electronic device further comprises at least one digital information display device for displaying the information, and a power source for powering the electronic assembly. development of information.

The present invention also relates to a method of manufacturing a portable electronic device capable of developing information, the portable electronic device comprising a body arranged to be attached to a user and at least one electronic assembly to develop the information, the body of the portable electronic device consisting of a layer of plastic material which gives the portable electronic device a shape and a thickness, the method being characterized in that it comprises the steps of: overmolding on an outer face of a first impervious plastic film a layer of plastic material which constitutes the body of the portable electronic device; mounting the electronic information processing assembly on the side of an inner face of the first impermeable plastic film, and bonding a second impervious plastic film on the first impermeable plastic film, so as to delimit between the first and second impermeable plastic films a sealed pocket in which is housed the electronic assembly of information development.

With these features, the present invention provides a method of manufacturing a portable electronic device wherein a sealed plastic film is overmolded with a plastic material which constitutes the body of the portable electronic device. It is only after this stage of the manufacturing process according to the invention that the electronic assembly for producing the information can be mounted on the sealed plastic film. In other words, the assembly step of the electronic assembly of information development is done after completion of the body of the portable electronic device. There is therefore no risk that the electronic assembly of information development is exposed to manufacturing conditions likely to damage or even destroy it. Furthermore, the manufacturing method according to the invention offers complete freedom as to the choice of the plastic material used to make the body of the portable electronic device. In particular, there is no limitation with respect to the temperature at which the overmoulding operation is carried out.

According to a complementary feature of the method of the invention, before the overmolding step of the plastic material which constitutes the body of the portable electronic device, the first impervious plastic film is hot formed to give the first impervious plastic film a profile. research.

Other features and advantages of the present invention will be more clearly apparent from the following detailed description of an embodiment of the flexible portable electronic device according to the invention, this example being given for purely illustrative and not limiting purposes only. in conjunction with the accompanying drawing in which: <tb> fig. 1 <SEP> is a top view of the portable electronic device according to the invention; <tb> fig. 2 <SEP> is a longitudinal sectional view of the portable electronic device according to the invention; <tb> figs. 3A and 3B <SEP> are schematic views illustrating the method of thermoforming the first impermeable plastic film, and <tb> fig. 4 <SEP> is a schematic view illustrating the overmoulding step of the first impermeable plastic film of FIGS. 3A and 3B.

The present invention proceeds from the general inventive idea of overmoulding an impermeable plastic film with a plastic material to form the body of a portable electronic device. Only after the overmolding operation has been carried out, is it mounted on the waterproof plastic film the electronic components necessary for the operation of the portable electronic device. Subsequently, a second impermeable plastic film is secured to the first impermeable plastic film so as to delimit a perfectly sealed enclosure in which the electronic components are protected from moisture. Thanks to these characteristics, there is complete freedom in the choice of the plastic material in which the body of the portable electronic device is made. It may be, for example, an elastomeric material which is known that moisture and gases can diffuse through. However, since the elastomer body is coated on its side which carries the electronic components of a sealed plastic film, the electronic components are perfectly protected, the sealed plastic film preventing the progression of moisture and gases. It is also not necessary to worry about the processing temperature of the material in which the body of the portable electronic device is made. Indeed, the overmoulding step of the body occurs before the component mounting step. Therefore, the manufacturing steps which, if necessary, involve high temperatures are completed during the assembly of the electronic components, so that these components are not likely to be damaged or destroyed by heat.

Fig. 1 is a top view of the portable electronic device according to the invention and FIG. 2 is a longitudinal sectional view of the portable electronic device of FIG. 1. Designated as a whole by the general reference numeral 1, the portable electronic device according to the invention comprises a body 2 consisting of a layer of plastic material which gives the portable electronic device 1 a shape and a thickness. The body 2 may be made of any plastic material such as, but not limited to, an elastomer.

According to the invention, a first sealed plastic film 4 serves to coat the layer of plastic material which constitutes the body 2 of the portable electronic device 1. To achieve this result, we begin (see Fig. 3A and 3B) by hot forming the first sealed plastic film 4 to give it the desired shape. This technique consists in hot pressing the first sealed plastic film 4 in a first mold 6 comprising two impressions 8a and 8b which have complementary shapes corresponding to the profile that is to be given to the sealed plastic film 4. Note that this operation is optional and depends only on the fineness of the form to be replicated. If necessary, this operation can be performed at the same time as the molding operation described below.

After hot forming and subsequent cooling, the first sealed plastic film 4 is overmolded with a flexible plastic material, for example an elastomer, in which the body 2 of the portable electronic device 1 is to be made. This technique is commonly referred to as its name Anglo-Saxon Film Insert Molding. For this purpose (see FIG 4), the first sealed plastic film 4 is placed in a second mold 10, an upper portion 12 against which the first sealed plastic film 4 is plated has a profile that matches that of the first sealed plastic film 4 , and a lower portion 14 of which has savings 15 at the places where it is desired to inject the plastic material in which the body 2 of the portable electronic device 1 is to be made.

After the manufacturing steps described above, there is obtained a plastic body 2 which has substantially the shape of a band or a bracelet. This body 2 of plastic material is coated on the side where is to be mounted an electronic assembly 16 for producing information of a first sealed plastic film 4. For this purpose, the body 2 of the portable electronic device 1 has, in one its length, a cavity 18 in which is housed the electronic assembly 16 to develop information. In the example shown in the drawing, the portable electronic device 1 is intended to develop in particular a time information. For this purpose, the electronic assembly 16 comprises a display device 20 such as a liquid crystal cell in which is disposed a light guide 22 provided to illuminate the display device 20 from the rear. The assembly is completed by a printed circuit board 24 on which are mounted the various integrated and discrete electronic components 26 necessary for the proper functioning of the portable electronic device 1 such as, in particular, a time base. The printed circuit board 24 is connected to the display device 20, to the light guide 22 as well as to a rechargeable battery 28 by means of a plurality of connectors 30. The rechargeable battery 28 is powered by at least one and , preferably two solar cells 32 which are advantageously housed in the strands 34 of the bracelet.

The manufacture of the portable electronic device 1 according to the invention is completed when one secures a second sealed plastic film 36 on a periphery 38 of the first sealed plastic film 4. The bonding can be effected by bonding or heat-sealing. The two first and second sealed plastic films 4 and 36 thus delimit between them a perfectly sealed cavity 40 inside which is housed the electronic assembly 16 for producing the information. Alternatively, it is also possible to secure the second sealed plastic film 36 over the entire surface of the first sealed plastic film 4.

It goes without saying that the present invention is not limited to the embodiment which has just been described and that various modifications and simple variants can be envisaged by those skilled in the art without departing from the scope of the invention. as defined by the claims appended to this patent application. In particular, by virtue of the features of the present invention, a portable electronic device 1 is obtained in which the electronic components that form the electronic information-processing assembly 16 are mounted on the body 2 of the portable electronic device 1 with interposition of a first sealed plastic film 4 between the electronic components and the body 2. Therefore, even if the material selected for producing the body 2 of the portable electronic device 1, for example an elastomer, allows the diffusion of moisture, the electronic components are perfectly protected thanks to the presence of the first waterproof plastic film 4 which acts as a barrier against moisture. Moreover, since the step of manufacturing the body 2 of the portable electronic device 1 occurs before the assembly of the electronic components, it is not limited by the temperatures at which the plastics must be worn to be able to make the body 2. In this case, In this case too, there is complete freedom in the choice of plastic materials.

Claims (7)

1. A portable electronic device capable of producing information, the portable electronic device (1) comprising a body (2) arranged to be attached to a user and at least one electronic assembly (16) for developing the information, the body (2) the portable electronic device (1) consisting of a layer of plastic material which gives the portable electronic device (1) a shape and a thickness, characterized in that the portable electronic device (1) comprises a first plastic film sealing member (4) which serves to coat the layer of plastic material, and a second sealed plastic film (36) secured to the first sealed plastic film (4), and in that the electronic assembly (16) for forming the information is disposed between the first and second sealed plastic films (4, 36). 2. Portable electronic device according to claim 1, characterized in that the body (2) of the portable electronic device (1) consists of a layer of flexible plastic material. 3. Portable electronic device according to claim 2, characterized in that the body (2) of the portable electronic device (1) is made of a flexible and elastic polymer. Portable electronic device according to one of claims 1 to 3, characterized in that the portable electronic device (1) further comprises at least one digital information display device (20) for displaying the information, and a power source for powering the electronic information development assembly. 5. Portable electronic device according to claim 4, characterized in that the power supply source comprises a rechargeable battery (28) powered by at least one solar cell (32). 6. A method of manufacturing a portable electronic device (1) capable of producing information, the portable electronic device (1) comprising a body (2) arranged to be attached to a user and at least one electronic assembly (16). for producing the information, the body (2) of the portable electronic device (1) consisting of a layer of plastic material which gives the portable electronic device (1) a shape and a thickness, the method being characterized in that it includes the steps of: - overmolding on an outer face of a first sealed plastic film (4) the layer of plastic material which constitutes the body (2) of the portable electronic device (1); - mounting the electronic information processing assembly (16) on the side of an inner face of the first sealed plastic film (4), and - securing a second sealed plastic film (36) on the first sealed plastic film (4), so as to define between the first and second sealed plastic films (4, 36) a sealed cavity (40) in which is housed all electronic information system (16). 7. A method of manufacturing a portable electronic device according to claim 6, characterized in that it comprises the step which consists, before the overmolding step of the plastic material which constitutes the body of the portable electronic device, to form to hot the first sealed plastic film (4) to give the first sealed plastic film (4) a profile sought.